Pages into the report released Saturday on the death of 19 wildland firefighters in the Yarnell Hill Fire in late June, investigators discuss “fog and friction,” a military term that describes the challenges soldiers face trying to communicate, understand and respond in the heat of combat. “Fog” refers to the chaos of battle and “friction” to ambiguous information, fatigue and unexpected events.

“Fog and friction” also bedevil wildland fire operations, the investigation team concluded in the 116-page report. “The Yarnell Hill Fire had plenty of fog and friction, as does any other fire that quadruples in size in a few hours, threatens people and homes and required the integration of many different types of air and ground resourc­es.”

The investigators concluded that the crew acted on its own without instructions from command, who so completely lost track of them and thought the crew was headed away from the fire instead of into the path of the abruptly shifting fire front. During a critical 30 minutes when the crew was out of radio contact and command was unaware of their position or intention, winds shifted radically, the fire took a 90-degree turn and doubled its speed. The flames caught the crew in a “non-survivable” canyon choked with brush just 600 yards from the safety of the ranch they’d set out for on a roughly 1.6-mile trek, apparently unaware of the abrupt change in fire behavior.

File photo of the Yarnell Hill Fire, which killed 19 firefighters.

The report carefully avoided placing blame or detailing how the controllers lost track of the crew, but highlighted problems with radio communications — which have plagued wildland firefighting operations elsewhere.

The crew did not have GPS locators and an air tanker searching for them did not know their location and therefore where to drop retardant.

The report documents the tragedy in chilling detail, while leaving many of the most agonizing and vital questions unanswered.

The fatal chain of events started on June 30, as the Granite Mountain crew rested in the safety of an already burned area — referred to as the “black.”

They could see the seemingly distant fire, which was bearing down on Yarnell — eventually consuming more than 100 homes. Radio calls from aircraft, evacuators, firefighters and command filled the airwaves.

Safe on the burned ridge, some of the men took pictures and texted family. Those images would later be splashed across the news.

The men then left the relative safety of the “black” and headed toward a ranch, which was considered another “bomb-proof” safe zone.

They could have reached the ranch along a crude road, but elected instead to cut through a grassy box canyon. The route appeared to offer a short cut, but at the cost of losing sight of the fire and plume of smoke.

On the heels of the tragedy, family, firefighters and the community were tormented by two haunting questions: How could a team of talented men who fought countless fires die so easily? And what could be done to prevent it from happening again?

The investigators lay out questions for firefighters, incident managers and researchers to ponder and possibly make changes in their own organizations.

They also offer several suggestions, including reviewing communications plans, reducing hazardous fuels and improving suppression efforts in communities at high risk for wildfires.

But the report never breaks through the speculation to offer a clear explanation for the tragedy.

The investigation team concludes that given the information they had, the team did what they thought was best by heading to the Boulder Springs Ranch, a safe zone 1.6 miles away from their lunch spot so they could re-engage with the fire they could see burning toward Yarnell.

No one in operations asked the crew to move. The team decided to head for the ranch, perceiving no risk of the fire overtaking them, according to the report.

Investigators concluded the deadly path through the box canyon must have looked faster than continuing to follow a road around the canyon’s rim. But once they moved into the box canyon, the crew lost sight of the fire and a feel for the abrupt wind shift.

But why would the crew leave the safe zone?

“If they stay in the black, they do no good. If they move, they might do some good even if they do not know what that good will look like. They think they can move without it being especially risky,” the report concluded.

The Yarnell Hill area had not burned in some 45 years, which primed it for a devastating fire during an extreme drought, the report concludes.

A lightning strike had triggered the fire two days earlier, on Friday, June 28, west of Yarnell, one of four fires started that day. By Saturday, the fire has grown to 100 acres and by Sunday to 300 acres. That’s when the Granite Mountain crew went to work clearing fire lines along the fire’s edge.

When the advancing fire forced their lookout to withdraw, the investigation team concludes the division supervisor likely took over and the firefighters exercised their own vigilance.

The men headed southeast away from their lunch spot, descending into a valley on a two-track road. They then left the road, taking the most direct route to the ranch.

“The (investigation) team believes the crew was attempting to reposition so they could re-engage,” the report says with the Yarnell Hill Fire.

The report concludes the men weren’t attempting to save the ranch, since it was considered a safe zone. That conclusion stands in contrast to speculation published in media accounts after the tragedy.

Throughout the day, radio communications presented a challenge, with some radios not programmed with appropriate tone guards so that heavy traffic jammed up the signals.

As the fire grew rapidly, shifting crews and a change in the command and categorization of the fire spawned confusion.

Although officials had communications with the crew throughout the day, no one knew where the team was going once they left the black. The team’s own lookout thought they were in a safe area.

“The (investigation) team believes this is due to brief, informal and vague radio transmissions and talk-arounds that can occur during wildland fire communications.”

The Granite Mountain crew, meanwhile, had watched the fire burn away from them all day. They didn’t know that soon after they left the ridge the fire changed direction and was coming toward them.

Although they received word that a weather report forecast predicted high winds and storm activity, it is unclear if the men considered the information when they decided to head toward the ranch.

Officials mistakenly believed the team was actually heading northeast away from the fire.

They lost contact with the men for some 30 minutes.

“There is much that cannot be known about the crew’s decisions and actions prior to their entrapment and fire shelter deployment at around 16:42,” according to the report.

Commanders did make contact with the crew moments before they deployed their shelters.

“Yeah, I’m here with Granite Mountain Hotshots, our escape route has been cut off. We are preparing a deployment site and we are burning out around ourselves in the brush and I’ll give you a call when we are under the sh ... the shelters,” one man radioed.

Commanders had a large air tanker in the area ready a drop of flame retardant, but over the next four minutes the pilots could not determine the location of the trapped Hotshots.

When firefighters later found the men’s bodies, 600 yards west of the ranch, some were still inside their shelters and others lay partly unprotected on the ground.

The report says the men had less than two minutes to clear brush from the ground and get into their shelters. Many were still deploying their shelters when the fire overtook them. The shelters are designed to protect firefighters briefly from radiant heat or flames that pass quickly over, but began to come apart above 1,200 degrees. With temperatures ex­ceeding 2,000 degrees, they had no chance — in or out of their shelters.

The report concludes that the incident team managing the fire made reasonable decisions and found no indication of reckless actions.

“This report does not identify causes in the traditional sense of pointing out errors, mistakes and violations, but approaches the accident from the perspective that risk is inherent in firefighting.”

Hellsgate and Payson Fire Department say they plan to have firefighters go through the report individually and then review it by shift.